Browsing by Issue Date, starting with "2018-11-13"

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Thiophene-Vinylene-Thiophene-Based Donor-Acceptor Copolymers with Acetylene-Inserted Branched Alkyl Side Chains To Achieve High Field-Effect Mobilities
(2018-11-13)
Chiou, De-Yang
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Su, Yen-Chen
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Hung, Kai-En
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Hsu, Jhih-Yang
;
Hsu, Tze-Gang
2-Alkyl((1))alkyl((2))-type aliphatic side chains with a branching point position at the C-2-position (such as 2-ethylhexyl or 2-octayldodecyl) have been widely implanted into numerous donor-acceptor conjugated copolymers for solution processable transistors or organic solar cells. However, the tertiary branching site located at the second carbon inevitably imposes steric hindrance that twists the main-chain coplanarity and attenuates interchain interactions. In this research, we developed a new two-dimensonal thiophene-vinylene-thiophene (TVT) derivative where a carbon-carbon triple bond is inserted between the thiophene unit and the 2-octyldodecyl group. This acetylene-incorporated TVT (aTVT) was copolymerized with 5,10-di(thiophen-2-yl)naphtho[1,2-c:5,6-c']bis-([1,2,5]thiadiazole) (DTNT) and 5,6-difluoro-4,7-di(thiophen-2-yl[benzo][1,2,5]thiadiazole (DTFBT) to form the polymers PaTVT-NT and PaTVT-FBT, respectively. PTVT-FBT, without the triple bond, was also prepared for comparison. The insertion of a linear triple bond moves the tertiary carbon away from the main chain to reduce the steric hindrance, thereby improving the main-chain coplanarity and facilitating the interchain interactions. The acetylene-incorporated copolymers show better thermal stability, red-shifted absorption spectra, stronger intermolecular aggregation, lower-lying electron affinity, and much higher solid-state crystallinity. Due to the linear and coplanar polymeric backbone supported by theoretical calculation, PaTVT-NT exhibits high crystallinity and adopts strong stacking with an edge-on orientation in the thin film evidenced by 2D-GIXRD, leading to a high p-type OFET mobility up to 1.27 cm(2) V-1 s(-1) with an on-off ratio of 9.22 X 10(5). This value represents the highest value among the NT-based polymers. PaTVT-FBT also achieved a high mobility of 0.78 cm(2) which greatly outperforms the corresponding nonacetylene PTVT-FBT counterpart. Most importantly, the preparation of 2-alkyl((1))alkyl((2))-acetylenyl side chain is synthetically feasible, which can be easily applied to create new conjugated polymers for high-performance solution-processable optoelectronics.
Interface-Controlled Synthesis of Au-BINOL Hybrid Nanostructures and Mechanism Study
(2018-11-13)
Patlolla, Shashank Reddy
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Kao, Chen-Rui
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Yeh, Ai-Hsuan
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Lin, Hung-Min
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Chuang, Yu-Chun
The combined functionality of components in organic inorganic hybrid nanomaterials render them efficient nanoreactors. However, the development in this field is limited due to a lack of synthetic avenues and systematic control of the growth kinetics of hybrid structures. In this work, we take advantage of an ionic switch for regio-control of Au-BINOL(1,1'-Bi-2-naphthol) hybrid nanostructures. Aromatic BINOL molecules assemble into nanospheres, concomitant with the growth of the Au nanocrystals. The morphological evolution of Au nanocrystals is solely controlled by the presence of halides in the synthetic system. Here we show that quaternary ammonium surfactants (CTAB or CTAC), not only bridging Au and BINOL, but also contributing to the formation of concentric or eccentric structures when their concentrations are tuned to the range of 10(-5) to 10(-3) M. This facile strategy offers the potential advantage of scalable production, with diverse functional organic inorganic hybrid nanocomposites being produced based on the specific archetype of Au-BINOL hybrid nano composites.
Ultrafast nonradiative transition pathways in photo-excited pyrazine: Ab initio analysis of time-resolved vacuum ultraviolet photoelectron spectrum
(2018-11-14)
Mignolet, Benoit
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Kanno, Manabu
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Shimakura, Noriyuki
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Koseki, Shiro
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Remacle, Francoise
The internal conversion of photo-excited pyrazine, which occurs rapidly on a time scale of about 20 fs, has long been considered to proceed via a conical intersection between the optically bright S-2 (B-1(2u), pi pi*) and dark S-1 (B-1(3u), n pi*) states. Since 2008, several theoretical studies have raised the possibility that other dark states S-3 ((1)A(u), n pi*) and S-4 (B-1(2g), n pi*) may participate dominantly in the early stage of the nonradiative decay of S-2. To clarify this issue, being motivated by the recent pump-probe experiment by Horio et al. [J. Chem. Phys. 145 (2016) 044306], we calculated vacuum ultraviolet photoelectron spectra for ionization from each of the four excited states. Comparison was made with the measured time-resolved photoelectron spectrum exhibiting a temporally varying multi-band structure. We confirmed no contribution of S-3 or S-4 and thus the validity of the conventional two-state (S-2 -> S-1) picture for ultrafast nonradiative transition in pyrazine.
Unusual rotating magnetocaloric effect in the hexagonal ErMnO3 single crystal
(2018-11-14)
Balli, M.
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Jandl, S.
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Fournier, P.
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Vermette, J.
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Dimitrov, D. Z.
It is known that orthorhombic RMnO3 multiferroics (R = magneticrareearth) with low symmetry exhibit a large rotating magnetocaloric effect because of their strong magnetocrystalline anisotropy. In this paper, we demonstrate that the hexagonal ErMnO3 single crystals also unveil a giant rotating magnetocaloric effect that can be obtained by spinning them in constant magnetic fields around their a or b axes. When the ErMnO3 crystal is rotated with the magnetic field initially parallel to the c axis, the resulting entropy change reaches maximum values of 7, 17, and 20 J/kg K under 2, 5, and 7 T, respectively. These values are comparable to or even larger than those shown by some of the best orthorhombic phases. More interestingly, the generated anisotropic thermal effect is about three times larger than that exhibited by the hexagonal HoMnO3 single crystal. The enhancement of the rotating magnetocaloric effect in the hexagonal ErMnO3 compound arises from the unique features of the Er3+ magnetic sublattice. In fact, the Er3+ magnetic moments located at 2a sites experience a first-order metamagnetic transition close to 3 K along the c axis resulting in a peaked magnetocaloric effect over a narrower temperature range. In contrast, the "paramagnetic" behavior of Er3+ magnetic moments within the ab plane produces a larger magnetocaloric effect over a wider temperature range. Therefore, the magnetocaloric effect anisotropy is maximized between the c and the ab directions, leading to a giant rotating magnetocaloric effect.
La6Si4S17:Ce3+: luminescence and lighting applications of a novel green-emitting phosphor
(2018-11-14)
Yang, Jiun-Yih
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Dutta, Somrita
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Chen, Teng-Ming
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應用化學系
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Department of Applied Chemistry
An efficient green-emitting La6Si4S17:Ce3+ phosphor was synthesized using a solid-state method. The phosphor exhibits a triclinic structure as the main phase. A broad green emission is observed upon excitation at 420 nm with a quantum efficiency of 83%. A white LED fabricated with the phosphor is promising for use in solid-state lighting applications.
NEURAL NETWORK PROCESSING SYSTEM
(2018-11-15)
Tuo-Hung HOU
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Chih-Cheng CHANG
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Jen-Chieh LIU
A neural network processing system includes at least one synapse and a neuron circuit. The synapse receives an input signal and has an external weighted value and an internal weighted value, and the internal weighted value has a variation caused by an external stimulus. When the variation of the internal weighted value accumulates to a threshold value, the external weighted value varies and the input signal is multiplied by the external weighted value of the synapse to generate a weighted signal. A neuron circuit is connected with the synapse to receive the weighted signal transmitted by the synapse, and calculates and outputs the weighted signal. The present invention can simultaneously accelerate the prediction and learning functions of the deep learning and realize a hardware neural network with high precision and real-time learning.
Idarucizumab-facilitated intravenous thrombolysis in acute ischemic stroke: A therapeutic strategy requiring further investigation
(2018-11-15)
Hsiao, Yu-Jen
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Tsai, Yi-Te
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Tsai, Li-Kai
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Fang, Chen-wen
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影像與生醫光電研究所
Radiation Therapy Outcomes Models in the Era of Radiomics and Radiogenomics: Uncertainties and Validation
(2018-11-15)
El Naqa, Issam
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Pandey, Gaurav
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Aerts, Hugo
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Chien, Jen-Tzung
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Andreassen, Christian Nicolaj
Electric field-controlled transformation of the eigenmodes in a twisted-nematic Fabry-Perot cavity
(2018-11-15)
Gunyakov, V. A.
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Timofeev, I., V
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Krakhalev, M. N.
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Lee, W.
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Zyryanov, V. Ya
The polarized optical states in the transmission spectrum of a twisted-nematic Fabry-Perot cavity with the distinctly broken Mauguin's waveguide regime have been theoretically and experimentally investigated. Specific features of the electric field-induced transformation of the polarization and spectral characteristics of eigenmodes of the neighboring series at the overlap resonant frequencies have been examined. It is demonstrated that the linear polarizations of eigenmodes at the cavity boundaries remain nearly orthogonal and their frequency trajectories reproduce the avoided crossing phenomenon. The experimental data are confirmed analytically and by the numerical simulation of light transmission through the investigated anisotropic multilayer with the use of a Berreman matrix method. The results obtained can be generalized to any materials with the helix response.
HYDROGEN SENSING DEVICE
(2018-11-15)
Yuan-Chieh TSENG
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Jaw-Yeu Liang
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Yun-Chieh Pai
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Yu-Jung Chou
;
Wen-Chin Lin
A hydrogen sensing device includes a multi-layered structure member. The multi-layered structure member includes a stack of alternatingly disposed magnetic layers and non-ferromagnetic layers. One of the magnetic layers is a topmost layer of the multi-layered structure member. The topmost layer includes a palladium-based material to detect hydrogen.
Modelling Software-Defined Networking: Software and hardware switches
(2018-11-15)
Singh, Deepak
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Ng, Bryan
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Lai, Yuan-Cheng
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Lin, Ying-Dar
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Seah, Winston K. G.
In Software-Defined Networking (SDN), a switch is a forwarding device that moves data packets in a network. A software switch handles forwarding functions in software and thus cannot forward packet at line speed while a hardware switch leverages optimised forwarding hardware to forward packets at line speed. However, there has been very little research in the literature to help network engineers understand the tradeoffs in choosing one over the other. In this paper, we develop a unified queueing model for characterizing the performance of hardware switches and software switches in SDN. The unified queueing model is an analytical tool for engineers to predict delay, packet loss and throughput in their SDN deployments. Existing queueing models of SDN have focused on performance analysis of software switches, while our work presented herein is the first to present a unified analysis of hardware and software switches. Our proposed models exhibit errors below 5% compared to simulation. Between a hardware and software switch, the evaluation shows that a hardware switch achieves an average 80% lower delay and up to 100% lower packet loss probability compared to a software switch. The more a hardware switch involves the controller for decisioning, the lower the gains in terms of packet delays through the switch.
Concomitant SK current activation and sodium current inhibition cause J wave syndrome
(2018-11-15)
Chen, Mu
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Xu, Dong-Zhu
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Wu, Adonis Z.
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Guo, Shuai
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Wan, Juyi
The mechanisms of J wave syndrome (JWS) are incompletely understood. Here, we showed that the concomitant activation of small-conductance calcium-activated potassium (SK) current (I-KAS) and inhibition of sodium current by cyclohexyl-[2-(3,5-dimethyl-pyrazol-1-yl)-6-methyl-pyrimidin-4-yl]-amine (CyPPA) recapitulate the phenotypes of JWS in Langendorff-perfused rabbit hearts. CyPPA induced significant J wave elevation and frequent spontaneous ventricular fibrillation (SVF), as well as sinus bradycardia, atrioventricular block, and intraventricular conduction delay. I-KAS activation by CyPPA resulted in heterogeneous shortening of action potential (AP) duration (APD) and repolarization alternans. CyPPA inhibited cardiac sodium current (I-Na) and decelerated AP upstroke and intracellular calcium transient. SVFs were typically triggered by short-coupled premature ventricular contractions, initiated with phase 2 reentry and originated more frequently from the right than the left ventricles. Subsequent I-KAS blockade by apamin reduced J wave elevation and eliminated SVF. beta-Adrenergic stimulation was antiarrhythmic in CyPPA-induced electrical storm. Like CyPPA, hypothermia (32.0 degrees C) also induced J wave elevation and SVF. It facilitated negative calcium-voltage coupling and phase 2 repolarization alternans with spatial and electromechanical discordance, which were ameliorated by apamin. These findings suggest that I-KAS activation contributes to the development of JWS in rabbit ventricles.
張敏郎　「啡」比尋常的退休生活
(2018-11-18)
李沛榆
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Department of Communication and Technology
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傳播與科技學系
「咖啡達人」張敏郎退而不休，用自己的力量讓更多人得以品嚐咖啡的美味。
國際踩舞祭　交流「舞」極限　
(2018-11-18)
黃俊軒
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許可晴
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Department of Communication and Technology
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傳播與科技學系
在前陣子一系列的熱身表演後，台中國際踩舞祭於11月9日正式開始，活動一連3天，於台中市政府周邊舉行，吸引許多民眾前來參與。
志同道合原來不只是因為緣分？
(2018-11-18)
許柏悅
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Department of Communication and Technology
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傳播與科技學系
達特茅斯學院於2018年發表的研究指出，好朋友之間會呈現出許多相似的大腦反應，原來「心靈相通」並不是只因為緣分，而是因為「腦袋相通」！
林東岳　轉換跑道的追夢創業人
(2018-11-18)
翁邦晏
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Department of Communication and Technology
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傳播與科技學系
從畢業替人家工作，到後來開設一間自己夢想中的店，林東岳是如何走上創業這條路的呢？
不只是一種人生　斜槓青年吳承峰
(2018-11-18)
顏筱娟
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Department of Communication and Technology
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傳播與科技學系
你有想過自己一生中會有多少標籤嗎？多重人生的斜槓青年正崛起。
新竹風收站　環保的大豐收
(2018-11-18)
李欣秝
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陳子與
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Department of Communication and Technology
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傳播與科技學系
自105年起設立的「風收站」為新竹市的資源回收帶來了新風貌。不僅在做回收時利用社區空間聯絡鄰里感情，民眾還能夠透過回收集點換贈品，讓更多人有了環保意識，也讓環保落實在生活中。
總編輯的話
(2018-11-18)
何浚捷
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Department of Communication and Technology
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傳播與科技學系
本期為喀報第302期，共計16篇稿件，以影音新聞與照片故事為主。頭題為黃淳妤的〈長篇連載漫畫　時間是一種語言〉，內容完整性高、主題特殊，並以非常有趣的方式呈現。歡迎大家閱讀。
你，療癒了嗎？
(2018-11-18)
彭姿敏
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Department of Communication and Technology
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傳播與科技學系
近年來，療癒風的興起，為人們忙綠的生活帶來另類的喘息方式，也為許多業者帶來商機。究竟為什麼大家會被這些「小物」療癒呢？你也被療癒了嗎？